de-ashi-bari is a judo technique. Imagine that you're stepping forward with your right leg. Just before it hits the ground, someone sweeps that foot leftwards, so that your body is dropping the weight onto the foot, but your foot is never quite making it to the ground. Meanwhile, their arms are making sure that your body does.
 Well, I say perfect. More near-perfect, I suppose, since I landed on my shoulder instead of my back. Wazari, rather than Ippon.